A giant Bowser appears in most of the Super Mario games as final boss (without encounting this as his own ability in Super Smash Bros and Mario & Luigi), so I do believe that this particular scene could fit very well with the saga!

PS: In the beginning, I thought to replace only the two characters ... but then I thought that the landscape didn't look like the Mushroom Kingdom, so I have decided to draw the whole thing starting from "zero" (thinking that it can be a good training also for myself). The houses are the same you can see in Super Mario Galaxy.